This invention relates to an agricultural apparatus and particularly to means for adjusting the depth of operation of a ground working tool thereof.
In our U.S. application Ser. No. 146,408, now U.S. Pat. No. 4,355,689, there is disclosed a flexible wing agricultural implement which comprises a plurality of separate frame sections pivotally coupled to one another and each incorporating ground wheels for supporting the frame sections relative to the ground. The whole implement is towed by a tractor and supports a plurality of ground working tools such as air seed drills. Each ground working tool is supported by a respective section of the frame and acts to dig into the ground to a predetermined depth, dependent upon the position of the frame section relative to the ground. In many cases, it is desirable to adjust the depth of working of the tool in the ground dependent upon the ground conditions or upon the crops concerned. This can, of course, be achieved by individual adjustment of each of the ground working tools relative to the respective frame section, but this is a long and laborious task with considerable opportunity for error. It is desirable therefore to provide a single adjustment mechanism which operates to adjust the depth of working of each of the ground working tools of the frame simultaneously.
A further problem which arises with this type of structure is that as the frame sections are pivotally mounted relative to one another to accommodate different levels, the common adjustment means must also accommodate such flexing of the frame sections relative to one another.